Magnetic separator for cane-crushing machinery



Dec. 10, 1929. STRUEBIG 1,738,739

MAGNETIC SEPARATOR FOR CANE CRUSHING MACHINERY Filed Dec. 31. 1928 Patented Dec. 10, 1929 l UNITED STATES PATENT OFFICE- LOUIS J. STBUEIBIG, OF ST. LOUIS, MISSOURI, ASSIGNOB TO FULTON IRON WORKS COIL PANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF DELAWARE MAGNETIC SEPARATOR FOR CANE-CBUSHING MACHINERY Application filed December a1, 1928. Serial No. 329,648.

This invention relates generally to machinery for operating on sugar cane or simi-' lar material, and more specifically to cane crushers and mills adapted for use in crushing and expressing juice from sugar cane, the predominant object of the invention being to provide such machinery with attractive magnetic means whereby pieces of iron or steel, or other material which responds to magnetism, may be attracted by the magnetic means and extracted from the mat of cane or bagasse as it passes through the machinery before such pieces of material have had an opportunity to do serious damage to parts of the machinery through which the cane or bagasse subsequently passes.

Prior to this invention much damage has been done to cane crushing machinery by pieces of metal which find their way into the mat of cane or bagasse which is being operated on by said cane crushing machinery. These pieces of metal may be bolts, nuts, bits of chalns, etc., which fall from parts of the crushing or other cane treating or handling machinery, and it is obvious when these pieces of hard metal pass between pairs of rolls forming parts of the cane crushing machinery that very serious damage may be done to said rolls. 7

Heretofore efforts have been made to provide cane crushing machinery with magnetic means for extracting such pieces of metal from the mat of cane or bagasse, but these efforts have proved unsuccessful, due principally to the fact that the magnetic element was located above the mat of cane or bagasse instead of below same as in the present invention, and also because said magnetic device was improperly positioned in the machine.

The cane crushing machinery with which my improved magnetic separator is employed is provided with rolls between which sugar cane or bagasse is passed for the purpose of crushing the cane, and expressing the juice therefrom, and in most cases these machines comprise each one or more mills and one or more crushers in advance of the mill or mills for preparing the cane for operation thereon by the mill or mills. Previously attempts have been made to extract iron or steel from the cane or bagasse before it reached the first crusher, and while this would be the ideal arrangement, it has thus far proved to be quite impossible, due to the fact that the mat of cane as it passes to the first crusher is usually several feet in thickness and the magnetic element would not function efliciently through such great space and not at allthrough a mat of such thickness. Due to the fact that it is not feasible to arrange a magnetic element either beneath orabove a cane carrier 0 erating in advance of the first crusher, conceived the idea of permitting the cane to pass through the first crusher before extracting the pieces of iron or steel therefrom. Be-

cause of the corrugated or ribbed nature of the rolls of the crusher it has been found that any pieces of metal in the mat of cane or bagasse will be forced to the bottom of said mat of cane or bagasse by said rolls as said mat passes through the crusher, and by positioning the magnetic device so that it operates against the bottom face of the mat of cane or bagasse any pieces of metal which may be in the mat and which have been forced to the lower portion thereof by the crusher will pass in such close proximity to the magnetic device that said magnetic device may readily extrafct said pieces of metal from the mat.

Serious damage to a crusher, and especially a precrusher, by pieces of iron or steel in the mat of cane passed therethrough, is unusual because of the lighter tonnage on a crusher, and due also to the fact that the large grooves and wide setting of the rolls permits rather large pieces of metal to pass through quite readily, and because the crusher top caps permit substantial lift of the top roll, thus permitting passage through the crusher of pieces of metal. The situation is entirely different, however, in the case of a mill with its close setting, turn plate, and heavy hydraulic loading, and it is to the mill that the great damage has been done heretofore by pieces of iron and steel in the mat of cane or bagasse. To eliminate the damage to the mills I associate the magnetic element of my invention immediately behind a precrusher in a double crusher, or behind. the crusher in a tandem havin but one crusher, and because the function 0 these crushers is to prepare the cane or other material for assage through the mill, said material will pass into the mill free from pieces of iron or steel which, 1f present in the material, would do damage to the mill.

Also, heretofore the magnetic devices have been placed at various places in the cane machines where conditions were not right for the extraction of pieces of metal from the mat of cane or bagasse, and hence the best results were not attained. In accordance with the present invention, the magnetic device is preferably located immediately adjacent to the scraper associated with a cane crusher, and in view of the fact that the mat of cane or bagassebreaks as it passes over said scraper, any pieces of metal in the mat will be loosened at the time of the break referred to, whereby said pieces of metal may be readily extracted from said mat by the ma netic device.

ig. 1 is a fragmentary vertical section of a cane crusher equipped with my improved magnetic separator.

Fig. 2 is a section on line 2-2 of Fig. 1.

In the drawing, wherein is illustrated one embodiment merely of the invention, A designates a cane crusher of ordinary constructlon, said cane crusher being provided with rotatable crushing rolls B and U between which the mat of cane is passed for the urpose of crushing same. The rolls B and are cooperativelv connected together by the usual gears and are preferably, though not necessarily, provided with alternate annular ribs and grooves D, so that the crushing operation may be more effectively performed. The rotatabl'e rolls B and G are supported in suitable bearings associated with the side frames of the crusher, as is commonly the case in v apparatus of this type.

Associated with the roll C of the crusher A is a scraper E of common construction except for one detail, which will presently be referred to herein. The scraper E which if desired may be comprised of a pair of elements secured together, as illustrated in Fig. 1, is mounted on a noncircular bar F which is extended transversely of the crusher, and the opposite circular end portions of said bar are mounted in suitable supports H. The front or nose portion of the scraper E which engages the roll C is serrated, as shown in Fig. 2, and said serrations enter between the annular ribs D on the roll. The bar F is held in its proper osition by the usual levers and tension rods not shown).

Positioned neath the rear end portion of the scraper E is the attractive magnetic separator of the invention, said separator preferably, though not necessarily, being in the form of a hollow cylindrical shell 1 which is preferably formed of brass and is rotatably extreme outer ends of said shell same is ro- 1,7ss,7se

mounted on a stationary shaft 2 extended transversely of the crusher. The shell 1 at its opposite ends preferably extends through apertures formed throu h the oppositely d18- posed side plates G of the crusher, and at the vided with upstanding flanges or ribs 3 w ich are intended for a purpose to be hereinafter set forth. The shaft 2 on which the shell 1 is mounted is non-rotatably supported at its opposite ends in suitable supporting bearings 4, and the shell 1 at its opposite ends is provided with hub portions '1' which extend through bearings 4, whereby said shell is rotatabliyl supported b said bearings. Also, said 5 aft is preferably hollow and the conductors by which the magnetic element is sup plied wit electrical energy pass through-said ollow shaft. The hub portion 1 at one .end of the shell extends outwardly beyond the adjacent bearings 4 and at the extreme outer end of said hub portion same has mounted thereon a sprocket wheel 5. In like manner the shaft C on which the crushing roll C is mounted has mounted thereon at an extreme outer end thereof a sprocket wheel 6 similar to the sprocket wheel on the shaft 2, and operating over said sprocket wheels 5 and 6 is a sprocket chain 7.

In view of the arrangement of the sprocket wheels 5 and 6 and the sprocket chain 7, it is obvious that when the crushing roll C is rotated the shell 1 will be likewise rotated.

Positioned within the shell 1 is a stationary magnetic core 8 which in cross-section is the approximate shape of a half circle, said core being secured to the shaft 2 in any suitable manner. The core 8 is provided wlth means for magnetizing same, but as such means are common it will not be necessary to describe same in detail herein.

10 designates a chute by which caiie or bagasse is conducted away from the rolls B and C, said chute bein suitably supported and having associated t erewith at its upper end an adJustable plate 11 whereby the dis- :tance between the upper end of the chute and the eripheral face of the shell 1 may be regu- The magnetic separator may be in the form of an electromagnet, or if preferred, same may be in the form of a permanent magnet or any other type of attractive magnetic device. Inany event, the magnetic separator will be magnetized, and when the crusher is in operation and when the precise magnetic device illustrated in the drawing is employed, magnetism will pass from the core 8 to the portion of the shell 1 which is located immediately adjacent to the curved face of said core to magnetize such portion of said'shell. The mat of cane passing between the rolls B and 'C will, of course, be subjected to great pres sure, and because of this fact and by the relationship of the scraper with respect to the roll III C, the mat of massed material will be caused to loosen and metallic foreign matter therein will become exposed and due to the downward pressure of the upper roll B, any pieces of metal in the mat will be forced through the mat to the bottom portion thereof. On passing from between the rolls B and C the mat-will "move along the scraper E and. sa d mat will then pass over the rear end of said scraper and move in contact with the rotating shell 1, as said mat passes to the chute 10, said shell 1 rotating in the direction of the mat. During the period that the mat is. passing to the chute 10 it contacts with the portion of the shell 1 which is magnetized by the core 8, and therefore any piees of metal which are in the mat will be drawn therefrom by the magnetism of the shell 1. The pieces of metal so drawn from the mat will adhere to the peripheral face of the rotating shell 1 until they reach the point where the Wall of said shell moves out of close proximity to the core 8, and when this point is reached the strength; of the magnetism exerted by the shell 1 will be so reduced that the pieces of metal will be released from the shell and will fall into a suitable receptacle (not shown).

It was stated hereinbefore that the scraper E is constructed as heretofore, except for one diflerence. This difference is the angular rear portion E thereof provided to cause the mat to .break the scraper. The result of this is that the of cane or bagasse mat becomes loose as the break occurs. hence,

.be understood that my due to this loose condition, any metal in the mat may be readily drawn therefrom by the magnetized shell 1. While I prefer to cause the mat :of material to break immediately before same passes over the magnetic separator, this is not absolutely necessaryas the pieces of iron and steel will be withdrawn from the mat even though this break does not occur. The upstanding flanges or ribs 3 on the shell 1 are provided 'to prevent juice from flowing over the ends of the shell and doing damage to the electrical appliances of the core 8, and said flanges or ribs also serve to guide the juice into. the usual juice pan (not shown).

The piecise magnetic separator illustrated in the drawing is not a part of my invention,

' said separators being obtainable on the market at the present time.

While I illustrate and describe a rotary magnetized element for drawing pieces of metal from the mat, I desire it to be understood that I may employ a stationary magnetzed element over which the mat of cane or bagassewould pass. and also while this specification describes the crushing machine as a sugar cane crushing apparatus, I wish it to improved arrangement may be employed as a part of any crush- .paratus having (Fig. 1) which is as it passes from the rear end of 'by the apparatus,

ing apparatus of the general type of a sugar cane crushing apparatus regardless of the class of material on which the apparatus opcrates. 4

I claim:

1. In combination with acane crushing apa pair of rolls provided withoverlapping ribs thereonto act upon amat of material so matter lodged therein, a magnetic separator comprising a magnetized element. positioned at a point beneath the path of travel of the mat of material being acted on by the appa-" ratus, said magnetized element being positioned so as to act on the mat of material after same has passed between said pair of rolls as toexpose metallic foreign and being adapted to draw metallic foreign matter from the mat of material as said mat I passes over said element.

2. In combination with a cane crushing a paratus having a pair of rolls provided wit overlapping ribs thereon to act upon a mat of material so as to expose metallic foreign matter lodged therein, a magnetic separator comprising a rotatable magnetized element positioned ata point beneath the path of travel of the mat of material being acted on by the apparatus, being positioned so as to act on the mat of material after same has passed between said pair of rolls and being adapted to draw metallic foreign matter from the mat of mate-' rial as saidmat passes over said element.

3. In combination with a cane crushing apparatus having a pair of rolls provided with overlapping ribs thereon to act upon a mat of material so as to expose metallic foreign matter lodged therein, comprising a rotatable positioned at a point beneath the path of travel of the mat of material being acted on said magnetized element being positioned so as to act on the 'mat of material after same has passed between the pair of rolls and being adapted to draw me tallic foreign matter from the mat of material as said mat passes over said element, and

means for transmitting rotary movement from a moving part of said cane crushing apparatus to said rotatable magnetized element.

. 4. In combination with a cane crushing ap-- paratus, a magnetic separator comprising a magnetized element positioned at a point beneath the path of travel of the mat of material being acted on by the apparatus, said magnetized element being adapted to draw metallic foreign matter from the mat of material as said mat passes over said element,

said magnetized element a magnetic separator magnetized elementand means for causing the mat of material to.

break at a point immediately adjacent to said magnetized element.

- 5. In combination with a cane crushing apparatus having crushing rolls and a scraperfor one of said rolls,

comprising a magnetized element positioned a magnetic separator at a point beneath the path of travel of the passes therefrom, whereby the material of the mat of material being acted on by the apparatus, said magnetized element being adapted to draw metallic foreign matter from the mat of material as said mat passes over" said element, said magnetized element being positioned adjacent to the discharge end said scraper and said discharge end of the mat will become loose and thus permit ready withdrawal of metallic foreign matter there.- g

from by said magnetized element.

\ v 9. In combination with a cane crushing apparatus comprising a crusher provided with cooperatin thereon an 'a mill, a magnetized element posiscraper being 50 arranged that the mat of. tioned at 8. point beneath the path of travel apparatus havin material will breakas it passes therefrom, whereby the material of the mat will become loose and thus permit ready withdrawal of metallicforeign matter therefrom by said magnetized element.

6. In combination with a cane crushing apparatus having crushing rolls and a scraper of the mat of'material being acted on by the apparatus and at a pdint behind the crusher so as to act on the mat of material after same has passed between'the cooperating rolls of the crusher, said magnetized element being adapted to draw metallic foreign matter from the mat of material as said mat passes over said element.

for one of said rolls, a magnetic separator Y In testimony that I claim the foregoing I comprising a rotatable magnetized element positioned at a point beneath the path of travel of the mat of material being acted on by the a paratus, said magnetized element being a apted to draw metallic foreign matter from'the mat of material as said mat passes over said element, said magnetized elementbeing charge end 0 said scraper and said discharge hereunto afiix my s'i ature.

L UIS J. STRUTEBIGQM positioned adjacent to the disend of the scraper being so arranged that the mat of material will break as it passes therefrom, whereby the material of the mat will become loose and thus permit ready withdrawal of metallic foreign matter therefrom by 'saidmagnetized element.

mat of material being acted on by the apparatus, said magnetized element being adapted to draw metallic foreign matter from the mat of material as said mat passes over said element, said magnetized element bein positioned beneath the discharge end of sai scraper and said discharge end of the scraper being so arranged that the mat of material will break as it passes therefrom, whereby the material of the mat will become loose and thus permit .ready withdrawal of metallic foreign matter therefrom by said magnetized element. V 8. In combination with a cane crushing crushing rolls and a scraper for one 0 said rolls, a magnetic separator comprising a magnetized element positioned at a point beneath the path of travel of the mat of material being acted on by the apparatus, said magnetized element being adapted to draw metallic foreign matter from the mat of material as said mat passes over said element, said magnetized element being- .so that the mat of material will break as it rolls having overlapped ribs 

